1. Field of the Invention
The present invention relates to an optical scanning device, and more particularly to an optical scanning device that supports a mirror part including a mirror reflecting surface from both sides by a torsion bar, where the mirror part swings around the torsion bar to be an axis, and deflects light reflected from the mirror reflecting surface.
2. Description of the Related Art
Conventionally, an optical scanning device is known that includes a movable plate including a reflecting surface to reflect incident light, a torsion beam to support the movable plate as a shaft, and a drive part to apply a drive force in a torsion direction on the torsion beam. In such a conventional optical scanning device, a configuration is known where ribs are formed on the back surface including a neighborhood of a connection part between the movable plate and the torsion beam in order to reduce deformation of the reflecting surface while rotating, as disclosed in Japanese Patent Application Laid-Open Publication No. 2010-128116 (which is hereinafter called “Patent Document 1”).
However, in a configuration disclosed in Patent Document 1, even though the deformation of the reflecting surface can be compensated for, there is a concern that stress can be concentrated in the vicinity of the rib structure so that destruction is likely to occur. Moreover, even where the destruction may not occur, because the stress is applied to the neighborhood of the rib structure, material fatigue can occur, which causes performance degradation.